Side ram motion for stokers



Jan. 24, 1928. 1,657,224

c. F. MILLER SIDE RAM MOTION FOR STOKERS Filed April 12, 1925 s Sheets-Sheet 1 ATTORNEY Jan. 24; 1925. y Y 1,657,224

6. F. MILLER SIDE HAI MOTION FOR STOKERS Filed April 12, 1923 3 Sheets-Sheet 2' cit:

al z'mizler WTNESSES' INVENTOR BY '%w z 1 1,657,224 0. F. MILLER SIDE RAN MOTION FOR STOKERS Filed April -12, 1923 3 Sheets-Sheet 5 t TX f I 1 7 TT0 RNEY A 1 Patented Jan. 24, 1928.

UNITED STATES CHARLES E. MILLER, OF MOORE, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELEC- 1,657,224 PATENT OFFICE.

TRIO AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SIDE RAM MOTION FOR STOKERS.

Application fled April 12, 1923. Serial No. 681,681.

ratus of the character designated which shall embody a durable and positive driving connection between the driving mechanism of the stoker and the auxiliary fuel feeding rams. It has for a further object to provide a driving mechanism for the purpose specified in which the movement of the auxiliary rams is co-extensive in time with that of the main ram, and it has for a still further object to provide means'for accurately adjusting the length of the stroke or the speed of travel of the auxiliary rams while the stoker mechanism is in operation, without regard to the position or direction of movement of the ram operating mechanism.

My invention has for a still further object to provide, in a stoker embodying a main retort and side fuel burning structure including movable members extending at substantially right angles to the main retort, improved means for imparting a motion to the movable members in a directiontransversely of the main retort.

These and other objects may be attained by means of a mechanism embodying the features herein described and illustrated in the accompanying drawings in which Fig. 1 is a plan view of a stoker of the type referred to and having mechanism for actuating the auxiliary rams in accordance with my invention; Fig. 2 is a partial transverse sectional elevation of the stoker taken on the line II'II of Fig. 1; Fig. 3 is a plan view showing, to a larger scale, a portion of the auxiliary ram driving mechanism illustrated in Fig. 1; Fig. 4 is a view partly in section and partly in elevation of the mechanism shown in Fig. 3; Fig. 5 is a sectional elee vation taken on the line VV of Fig. 3 and Fig. 6 is a plan showing a modified form of the apparatus shown in Fig. 3.

Referring to the drawings, I show in Fig. l a boiler casing 10 equipped with a mechanical stoker of the type in which my improved apparatus may "be utilized. It comprises a centrally-disposed main retort ll and a plurality of transversely extending alternately-disposed retorts 12 and tuyere banks 13. Ash removal is accomplished b means of dump grates 14 disposed on eac side of the furnace. Fuel is supplied to the furnace through a hopper 15 and a ram box 16, whence the main ram 17 forces the fuel into the main retort 11 and, upon suflicient accumulation therein, onto the side retorts 12 and tuyere banks 13. The driving mechanism of the stoker may be of any conventional type. As shown, the main ram 17. is connected through a rod 18 to a piston 19 disposed in a steam cylinder 20. Steam for the cylinder 20 is supplied through a conduit 22.

An auxiliary ram 23 is provided in each of the side retorts 12. The auxiliary rams on either side of the main retort 11 are actuated by a common rocker shaft 24 connected through a plurality of lever mechanisms with respective rams. mechanisms, as shown in Fig. 2, has two toggle levers 25 and 26. The lever 25 is rigidly secured to the rocker shaft 24, and the lever 26 is pivotally connected to a lug 27 provided on the auxiliary ram in such manner that an oscillating motion of the rocker shaft 24 will produce a reciprocating motion of the auxiliary rams connected. thereto.

As shown to a larger scale in Figs. 3 and 4, the rocker shafts 24 are driven from the main ram actuating means. Secured to the rod 18 is a cross-head 28, which is divided on its horizontal axis into two halves for facilitating removal. The two halves are coupled by means of a plurality of bolts 29, which also serve to rigidly secure the crosshead to a portion 31 of the rod 18 having a reduced diameter. Pivotally connected to each side of the cross-head are the horizontally-disposed curved levers 33 fulcrumed at 34 to a pair of radius rods 35 and 36, the other ends of which are pivotally connected to a vertically-disposed pin or shaft 37 The pin or shaft 37 is held in a supporting bracket 38 which is secured to the boiler front with a plurali. of bolts 39. The lower radius rod 36 18 provided with an extensive hub portion 41, the vertical thickness of which is such that the bearing contact between the hub 41 and pin 37 will support a substantial portion of the weight of the lever mechanism.

Interposed between the upper radius rod 35 and the lower radius rod 36 and pivotally Each of said lever connected to thepin 3i is a bell-crank 42 having lever arms .43 and 44 extending horizontally and disposed normally to each other. The end. portion of the lever arm 44 isformed into a segmental miter gear 45. This gear meshes with and drives a companion gear 46 which is rigidly secured to one of the rocker shafts 24, which shafts actuate the auxiliary rams; The lever arm 43 of the bell-crank 42 is provided with a hub portion 47 which is interposed between two horizontally disposed connecting rods 48 and 49, and pivotally connected thereto by means of a pin 51.

The opposite ends of the connecting rods 48 and 49 are freely connected to a vertically disposed pin 52 which is carried, as shown to a larger scale in Fig. 5, in two guide blocks 53 and 54. .Two oppositelyisposed surfaces of each of these guide blocks slidably engage internal bearing surfaces 55 and 56, Wl'ill'li are rovided in the curved lever 33. These bearing surfaces are arranged on the arcs of concentric circles having the pin 51 as their center, a circle dravrncentrally between the two surfaces having a radius equal to the effective length of the connecting rolls 48 or 49. By moving the 'uido blocks 53 and 54, as permitted by the bearing surfaces 55 and 56, from the position shown toward the fulcrum 34 of the lever, the leverv arm is reduced in effective length and the extent of the movement imparted thereby to theconneeting rods 48 and 49 is proportionally reduced.

For accurately adjusting the position of the guide blocks 53 and 54 in the curved lever 33, and for maintaining them inany desired location, I provide an adjusting screw 57 having a protruding end portion which may be adapted to engage a wrench or any equivalent means suitable for rotating the member. The adjusting screw is provided with shoulder portions 59 and 61 which are disposed on opposite sides of a retaining pin 62, which pin prevents axial movement of the adjusting screw. The re taining pin 62 is free to oscillate and is held in place by the cap 63, which is in turn rigidly secured to the curved lever 33by bolts 64. The adjusting screw 57 freely engages the retaining pin 62, and for purposes of assembly, the extended end portion 58 is manufactured separate from the remaining portion. The threaded portion of the adjusting. screw passes through a hole in the pin 52 having internal threads therein which engage respective threaded portions of the screw. In order to prevent the adjusting screw from striking the side wall of the curved lever 33, when the guide blocks are in engagement with the lever in a position remotely disposed from that shown in the drawing, the hollow portion 65 is extended in a horizontal plane an amount sufficient to provide proper clearance. B the above arrangement of mechanism, t e amount of motion imparted by the main ram actuating means to the auxiliary rams, may be varied while the stoker is in operation.

Under some circumstances, however, should it be found satisfactory to halt the operation of the stoker to make such adjustments, I may provide a simple and less expensive mechanism as shown in Fig. 6.

This may comprise a plurality of holes in the curved lever 33 arranged on the arc of a circle having the pin 51 as its center and a radius equal to the effective length of the connecting rods 48 or 49. By securing one end of said connerrting rods to one of the above mentioned holes by means of a suitable pin 52, the desired amount of travel of the auxiliary rams may be substantially procured.

The operation of my invention is as follows: Fuel is supplied to the hopper 15 and thence to the ram box 16. The main ram 17 forces the fuel into the main retort 11 and upon sufiicient accumulation therein. it overflows upon the side retorts 12 and tuyere banks 13 so as to cover the grate surface of the stokcr. The auxiliary rams 23 move to and fro to agitate and facilitate the advance of the fuel, and are driven from the main ram actuating means by the mechanism disclosed in my invention as is hereinafter set forth.

' The cross-head 28, which is secured to the main ram actuating rod 18, oscillates the curved lever 33 about the pin 34. This movement is conveyed to some extent to the connecting rods 48 and 4.) which in turn impart a rocker motion to the bell-crank 42. The miter gear portion 44 of the bell-crank 42 engages the segmental miter gear 46 which secured to the rocker shaft 24 and imparts an oscillating motion thereto. This motion is transmitted and is converted into a reciprocating motion by means of a plurality of toggle levers 25 and 26 to the auxiliary rams 23.

W'ith the above arrangement of mechanism, the auxiliary rams are positively connected to the main ram actuating means, no lost motion being involved. This is espccially desirous in stokers of the type here in referred to, in which the motion of the main ram, due to its direct connection with a piston disposed in a steam cylinder, is inl clined to be unsmooth or jerky.

Should it become necessary at any time to alter the extent of travel of the auxiliary rams, this may be accomplished by turning the adjusting screws 57 on each side of the stoker. The turning of the adjusting screw 57 moves the pin 52 and increases or decreases the distance between said pin and the fulcrum point 34 of the curved lever 33. This increase or decrease in length of one of the lever arms, results in an alteration in the amount of motion transmitted thereby to the connecting rods 48 and 49, which alteration is eventuall iliary rams 23' an a change in the extent of the movement thereof effected. It will be noted, that in myapparatus, a change in the length of stroke of the auxiliary fuel feed ng rams may be effected without any alteration whatsoever in the upper limit of travel, or in other words, the difference in extent of travel of the rams is entirely effected in the lower or substantially consumed fuel portion of the furnace. f

It is to be observed that m invention in its broader aspects is not limited in its application to a stoker havin a central retort and a side fuel burning sur ace of the underfeed type, as it might equally as well be used to operate the movable members of any side burning fuel surface which move transversely to the direction of motion of the main ram, as for example, the movable members of an overfeed grate section.

\Vhile I have shown my invention in but tWO forms, it will be obvious to those skilledm the art that it'is not so limited, but is susceptible of various other changes and.

modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed there'- upon as are imposed by the prior art or as are specifically set forth in the appended claim 5 \Vhat Iclaim is:

1. In a mechanical stoker, the combination of a main ram, a plurality of auxiliary rams substantially at right angles to the main ram, a rod having means for imparting a reciprocatory movement to the main ram, a rocker shaft connected through a plurality of lever mechanisms vwith the auxiliary rams, link mechanism including gear members associated with the rod for imparting an oscillatory movement to said rocker shaft, and a lever included in said link mechanism having a lever arm of variable length whereby the extent of the oscillatory movement of said rocker shaft may be varied.

2. In a mechanical stoker having a main central retort and a plurality of side retorts disposed transversely thereto, the combination of a main ram, a rod having means for imparting a reciprocatory movement thereto, ,a cross-head member rigidly secured to said rod, a plurality of auxiliary rams, rocker shafts connected through a plurality of respective lever mechanisms with said auxiliary rams, a plurality of link mechanisms includin gear members pi'votally connected to sai cross-head, whereby a reciprocating movement coincident with the reciprocatrons of the rod is imparted to the auxiliary rams through the respective rocker shafts, a lever included in each of transmitted to the aux-,

said link mechanisms having a lever arm of variable length, whereby the extent of the reciprocating movement of the auxiliary rams may be varied, and means including an adjusting screw for varying the length of said lever arm.

3. In a stoker embodyin a retort with a ram and a side fuel burning structure including movable members extending at substantial angles to the retort, means for imparting a motion to the movable members in a direction transversely of the main retort comprising a rod having means for actuating the ram, and suitable link mechanism associated with the rod for actuating the movable members, said link mechanism including a lever having a lever arm of fixed length and a lever arm of adjustable length, whereby the amount of movement of the movable members may be varied.

4. In a mechanical stoker embodying a retort with a ram and side fuel burningstructure including movable members extending at substantial angles to the retort, means for imparting a motion to the movable members in a direction transversely of the direction of movement ofthe ram comprising a rod having means for imparting a reciprocatory movement to the ram, and suitable link mechanism' associated with the rodfor imparting a reciprocatory movement to the movable members coincident with all movements of the ram, said link mechanism including a lever having a lever arm of fixed length and a lever arm of adjustable length, whereby the relative speed of travel of the member with respect to that of the ram may be varied:

5. In a mechanical stoker embodying a retort with a ram and side fuel burning structure including movable members extending at substantial angles to the retort, means for imparting a motion to the movable members in a direction transversely .of the direction of movement of the ram comprising a rod having means for imparting a Ieci rocatory movement to the ram, a rocker s aft connected through a plurality of lever mechanisms with the movable members, link mechanism including gear members associated with the rod for imparting an oscillatory movement to said rocker shaft, and a lever included in said link mechanism having a lever arm of variable length whereby the extent of the oscillatory movement of said rocker shaft may be Varied.

6. In a stoker embodying a. retort with a ram and a side fuel burning structure includin movable members extending at substantiai angles to the retort, means for imparting a motion to the movable members in 8. d1 rection transversely of the main retort comprising a rod having means for impartinga reciprocatory movement to the ram, and suitable link mechanism associated with the rod for imparting a reciprocatory movement to the movable members coincident with all movements of the ram, said link mechanisms including a lever having the point of applied load interposed between the fulcrum and the point of applied force, and having means for varying tie distance between the fulcrum and the point of ap lied load.

7, In a stoker em odying a retort with a ram and a side fuel burning structure includmovable members extending at substanangles to the retort means for imparting a motion to the movable members in a direction transversely of the main retort comprising a rod having means for imparting a reciprocatory movement to the ram, and suitable link mechanism associated with the rod for-imparting a recipro'catory movement to the movable members coincident with all movements of the ram, said link mechanism including a lever having the point of applied load interposed between the fulcrum and the point of applied force and having means including an adj ustin screw for varying the distance between t e fulcrum and the point of applied load.

8. In a mechanical stoker having a main central retort and a plurality of side retorts disposed transversely thereto, the combination of a main ram arranged within the central retort; auxiliary rams arranged within the side retorts, a rod having meahs for imparting a reciprocatory movement to the main ram, and suitable link mechanism associated with the rod for imparting a reciprocatory movement to the auxiliary rams co incident with all movements of the main ram said link mechanism including a lever having the point of applied load interposed between the fulcrum and the point of applied force and having means for varying the distance between the fulcrum and the point of ram, and suitable link mechanism associated with the rod for actuating the auxiliary ram. said link mechanism including a lever having a lever arm of fixed length and a lever arm of adjustable length, whereby the amount of movegient of the auxiliary ram may be varle 10. In a mechanical stoker having a main central retort and a side retort disposed transversely thereto, the combination of a main ram mounted to reciprocate within the central retort an auxiliary ram mounted to reciprocate within the transversely disposed side retort, a rod having means for imparting a reciprocatory movement to the main ram, and suitable link mechanism associated with the rod for imparting a reciprocatory movement to the auxiliary ram coincident with all movements of the main ram, said link mechanism including a lever having a lever arm of fixed length and a lever arm of adjustable length, whereby the relative speed of travel of the auxiliary ram with respect to that of the main ram may be varied.

In testimony whereof, I have hereunto subscribed my name this 9th day of April, 1923.

CHARLES F. MILLER. 

